x86/hyper-v: Include hyperv/ only when CONFIG_HYPERV is set

x86/hyper-v: Include hyperv/ only when CONFIG_HYPERV is set

Code is arch/x86/hyperv/ is only needed when CONFIG_HYPERV is set, the
'basic' support and detection lives in arch/x86/kernel/cpu/mshyperv.c
which is included when CONFIG_HYPERVISOR_GUEST is set.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jork Loeser <Jork.Loeser@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Simon Xiao <sixiao@microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: devel@linuxdriverproject.org
Link: http://lkml.kernel.org/r/20170802160921.21791-2-vkuznets@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>